C++/STL Algorithms Non modifying sequence operations/find first of
Use find_first_of function to search first occurrence of an element
/* The following code example is taken from the book
* "The C++ Standard Library - A Tutorial and Reference"
* by Nicolai M. Josuttis, Addison-Wesley, 1999
*
* (C) Copyright Nicolai M. Josuttis 1999.
* Permission to copy, use, modify, sell and distribute this software
* is granted provided this copyright notice appears in all copies.
* This software is provided "as is" without express or implied
* warranty, and with no claim as to its suitability for any purpose.
*/
#include <iostream>
#include <vector>
#include <deque>
#include <list>
#include <set>
#include <map>
#include <string>
#include <algorithm>
#include <iterator>
#include <functional>
#include <numeric>
/* PRINT_ELEMENTS()
* - prints optional C-string optcstr followed by
* - all elements of the collection coll
* - separated by spaces
*/
template <class T>
inline void PRINT_ELEMENTS (const T& coll, const char* optcstr="")
{
typename T::const_iterator pos;
std::cout << optcstr;
for (pos=coll.begin(); pos!=coll.end(); ++pos) {
std::cout << *pos << " ";
}
std::cout << std::endl;
}
/* INSERT_ELEMENTS (collection, first, last)
* - fill values from first to last into the collection
* - NOTE: NO half-open range
*/
template <class T>
inline void INSERT_ELEMENTS (T& coll, int first, int last)
{
for (int i=first; i<=last; ++i) {
coll.insert(coll.end(),i);
}
}
using namespace std;
int main()
{
vector<int> coll;
list<int> searchcoll;
INSERT_ELEMENTS(coll,1,11);
INSERT_ELEMENTS(searchcoll,3,5);
PRINT_ELEMENTS(coll, "coll: ");
PRINT_ELEMENTS(searchcoll,"searchcoll: ");
// search first occurrence of an element of searchcoll in coll
vector<int>::iterator pos;
pos = find_first_of (coll.begin(), coll.end(), // range
searchcoll.begin(), // beginning of search set
searchcoll.end()); // end of search set
cout << "first element of searchcoll in coll is element "
<< distance(coll.begin(),pos) + 1
<< endl;
}
/*
coll: 1 2 3 4 5 6 7 8 9 10 11
searchcoll: 3 4 5
first element of searchcoll in coll is element 3
*/
Use find_first_of function to search last occurrence of an element
/* The following code example is taken from the book
* "The C++ Standard Library - A Tutorial and Reference"
* by Nicolai M. Josuttis, Addison-Wesley, 1999
*
* (C) Copyright Nicolai M. Josuttis 1999.
* Permission to copy, use, modify, sell and distribute this software
* is granted provided this copyright notice appears in all copies.
* This software is provided "as is" without express or implied
* warranty, and with no claim as to its suitability for any purpose.
*/
#include <iostream>
#include <vector>
#include <deque>
#include <list>
#include <set>
#include <map>
#include <string>
#include <algorithm>
#include <iterator>
#include <functional>
#include <numeric>
/* PRINT_ELEMENTS()
* - prints optional C-string optcstr followed by
* - all elements of the collection coll
* - separated by spaces
*/
template <class T>
inline void PRINT_ELEMENTS (const T& coll, const char* optcstr="")
{
typename T::const_iterator pos;
std::cout << optcstr;
for (pos=coll.begin(); pos!=coll.end(); ++pos) {
std::cout << *pos << " ";
}
std::cout << std::endl;
}
/* INSERT_ELEMENTS (collection, first, last)
* - fill values from first to last into the collection
* - NOTE: NO half-open range
*/
template <class T>
inline void INSERT_ELEMENTS (T& coll, int first, int last)
{
for (int i=first; i<=last; ++i) {
coll.insert(coll.end(),i);
}
}
using namespace std;
int main()
{
vector<int> coll;
list<int> searchcoll;
INSERT_ELEMENTS(coll,1,11);
INSERT_ELEMENTS(searchcoll,3,5);
PRINT_ELEMENTS(coll, "coll: ");
PRINT_ELEMENTS(searchcoll,"searchcoll: ");
// search last occurrence of an element of searchcoll in coll
vector<int>::reverse_iterator rpos;
rpos = find_first_of (coll.rbegin(), coll.rend(), // range
searchcoll.begin(), // beginning of search set
searchcoll.end()); // end of search set
cout << "last element of searchcoll in coll is element "
<< distance(coll.begin(),rpos.base())
<< endl;
}
/*
coll: 1 2 3 4 5 6 7 8 9 10 11
searchcoll: 3 4 5
last element of searchcoll in coll is element 5
*/